One of the problems in accelerating a low mass to a high velocity is that the prime mover must accelerate itself in addition to the driven mass, thus placing a fundamental limit on the acceleration rate of any prime mover. Clutches solve this problem to some extent in that the energy stored in an accelerated high mass prime mover can be transmitted to a load through a clutch which can be engaged relatively rapidly. In clutches of the prior art, driving and driven members, having contact surfaces possessing a high coefficient of friction, are normally held apart in the quiescent state of the clutch to prevent compression of the surfaces. To engage the clutch, the members are moved into engagement by the application of a relatively low force. This required motion, however, creates a time constant which limits the acceleration rate of these clutches.
Sorkin U.S. Pat. No. 2,958,229 issued Sept. 4, 1959, for a variable speed drive discloses a device in which parallel input and output shafts each carry a plurality of thin, flexible hard metal disks. The shafts are positioned so as to form as assembly of overlapping interleaved disks, between which a pair of squeeze rollers are placed. To engage the clutch, the rollers apply a flexural force to the assembly, moving the disks together. The disks engage each other loosely, except along a narrow line of contact between the squeeze rollers enabling one shaft to drive the other. The excessive friction between the loosely engaged portions of the disks together with the required movement thereof impede the rapid acceleration of low mass loads by this device.